Less than two minutes into the first U.S. Senate debate in Massachusetts, incumbent Republican Scott Brown laid into Democrat Elizabeth Warren on the controversy surrounding her Native American heritage.Warren claimed to be "a Native American, a person of color," Brown said. "As you can see, she is not." Earlier this year, news surfaced that Warren had listed herself as a Native American in a faculty directory at Harvard Law School, and Republicans questioned whether Warren used the minority status to benefit her career. Brown began Thursday night&rsquo;s debate in...